Punching and riveting machine



Oct. 6, 1936. H. A. BERLINER 2,056,559

PUNCHING AND RIVETING MACHINE Filed Oct. 7, 1933 4 Sheets-Sheet 1 INVENTOR. f/mfir 17. 50% mm.

ATTORNEYS.

Oct. 6, 1936. H. A. BERLINER 2,056,559

runcnms AND RIVETING MACHINE Filed Oct. '7, 1933 4 Sheets-Sheet 2 TTORNEYS.

Oct. 6, 1936. H. A. BERLINER runcnme AND mvmme ummm Filed Oct. 7, 1933 4 Sheets-Sheet 3 nil WHY/2292:2224. 6 /M v ATTORNEY-9.

4 Sheets-Sheet 4 H. A. BERLINER PUNCHING AND RIVETING MACHINE Filed Oct. 7, 1933 ATTORNEYJ.

Oct. 6, 1936.

Patented Oct. 6, 1 936 UNITED STATES PATENT OFFICE runcnmo AND mva'rmc mom Henry A. Berliner, Washington, D. C. 7 Application October 7, 1933, Serial No. 692,573 8 Claims. 40!. 78-49) This invention relates to a punching and riveting machine.

This invention contemplates a riveter which is sufliciently light so that it can be handled by the operator without the need of any mechanical means for suspending and transporting the same?" It has been found that it is not essential to punching the hole through the work or metal members which are to be riveted that the same should be accomplished by a single heavy blow but that the punching operation can be performed by a succession of lighter blows. In view of this discovery it is proposed to use a light motor of the vibrating or single sho type which gives a succession of light blows in performing the punching and riveting operations. In other words, it is proposed to punch by a succession of light blows rather than a single heavy blow. The energy content of each blow is preferably within the elastic limit or yield point of the metal, the yield point being a well known variable depending upon the kind and character of the metal being punched. This permits the use of a much lighter motor, preferably of the pneumatic type, which in turn cuts down the overall weight of the machine. This permits the weight to be sumciently light so that the machine can be carried and transported by the operator unassisted by mechanical suspending and transporting means.

It has been found desirable in punching to use blows of a certain energy content and for riveting to use blows containing a different amount of energy. For example, in punching heavy material each blow would have such a large energy content that a like blow would completely flatten a soft rivet. Then too, in both punching and riveting, on certain occasions it is desirable to be able to regulate the energy content of the punching and riveting blows; for instance, this would permit a powerful machine to be used on light work by decreasing the intensity of the punching and riveting blows. This object has been achieved by throttling the exhaust which decreases the intensity of the blows.

It is also an object of this invention to provide a rivet feeder which is simple and certain in operation. This has been achieved by pneumatically ejecting the rivets from the rivet magazine into the rivet shoe and preferably by utiliz ing the exhaust pressure set up by the return stroke of the piston of the pneumatic motor for pneumatically feeding the rivets.

In the drawings:

Fig. 1 is a side elevation of the riveter.

Fig. 2 is an enlarged fragmentary side elevation partly in section of the riveter.

Fig. 3 is a section along the line 3-3 of Fig; 2.

Fig. 4 is a sectional view through the rivet ,magazine and punch showing the rivet shoe about to receive a rivet as the die retreats.

Fig. 5 is a view similar to Fig. 4 showing the shoe depositing the rivet in the punched hole just prior to the upsetting of the rivet.

Fig. 6 is a detail showing the position of the parts as the riveting is completed.

Fig. '7 is a section along the line 1-1 of Fig. 5.

Fig. 8 is a section along the line 88 of Fig. 6.

Fig. 9 is a section along the line 9-9 of Fig. 5.

Fig. 10 is a section along the line l0lll of Fig. 6.

Fig. 11 is a detail of the lower end of the rivet magazine and rivet shoe as the rivet is being ejected from the magazine into the shoe.

Fig. 12 is a view of the lower end of the rivet magazine showing the rivet stop in place.

Fig. 13 is a vertical section showing the position of the parts just prior to the punching of the work by vibration.

Fig. 14 is an elevation showing the position of the parts with the exhaust throttled as the rivet is being upset by vibration.

Fig. 15 is a section along the line |5l5 of Fig. 14.

The machine preferably has a unitary c-shaped frame made from some such light metal as duraluminum. The frame i is provided with hand grips 2 and 3 by means of which the operator holds the machine while operating the same.

Since it is an object of the invention to produce a machine of the above mentioned type light enough that the ordinary man can support the same manually while using the same, it is proposed to punch the hole and upset the rivet by a succession of light blows. To this end the frame I is provided with a head 4 in which is mounted any suitable motor of the vibrating type or of the single shot" type but preferably a pneumatic motor. Since this pneumatic motor of the vibrating type may be any of the well-known makes of pneumatic vibrators, such as the moving unit of the RV-lX Yoke Riveter made by the Chicago Pneumatic Tool Company and shown on page 20 of their Catalog No. 564 (Second Edition), Copyright February 1933, it is not shown here in detail and will not be described in detail. The vibrating pneumatic motor generally comprises a cylinder in which is mounted the plunger 5 which carries the set 6. In this form of pneumatic motor the power stroke of the plunger 5 s effected pneumatically through some such compressed gas as air which is fed into the cylinder through the air line 1 which is controlled by the intake valve 8. The exhaust is controlled by valve I2. The

'retum stroke of the plunger 5 is efiected through a coil spring [I of the compression type. The valve 8 is controlled by the finger trigger 9 pivoted at I9. The valve 8 may be any of the wellknown types such as the spring loaded ball check valve I29 which may be released by the arm I3 of the trigger 9 acting through the plunger I3I. The exhaust valve I2 likewise may be any suitable type such as the spring loaded ball check valve which is controlled by the arm I22 of the trigger acting through the plunger I23. As shown in the full lines, Figure 1, the. trigger 9 is in off position at which time both plungers I23 and the wire 24 I 3| are in projected position and both intake and exhaust valves closed so that compressed air is neither admitted into, not exhausted from, the

cylinder of the motor. In Fig. 2 the trigger 9 is shown in completely retracted position. If the trigger 9 is moved to the middle position, as shown in the dotted'lines inFig. 1, that is, be-

tween the released position shown in the full lines of Fig. 1 and the fully retracted position shown in Fig. 2, then the valve 8 will be open and at this .time air will be admitted into the cylinder but not permitted to exhaust. Plunger will execute a power stroke and remain in the projected position shown in Fig. 2. If the trigger 9 is now retracted fully to the position shown in Fig. 2, arm|22 acting through plunger I23 will open exhaust valve I2 which in the well-known way, will cause the piston I24, reciprocably mounted within the plunger 5, to reciprocate or vibrate thus effecting the succession of light blows upon the set 6.

If desired the succession of light blows may be obtained by the well-known "single shot type of pneumatic motor in which a single blow, preferably light, is struck for each pull of the trigger. With such a motor the hole will be punched or the rivet upset with fewer blows than is necessary where the vibrating or reciprocatory motor is used.

The lower end of the frame I carries the anvil I4 in which is reciprocably-und yieldably mounted the punch I5. The punch I5 is yieldably supported by the coil spring I8, the lower end of which is secured to the punch I5 as at I1 and the upper end of which is fixed in a wall of the anvil as at I8.

Since the punch I5 is yieldably mounted and while in projected position serves as a punch and while in retracted position serves as a portion of the anvil during the riveting operation, the punch 5 must necessarily be backed up by a suitable stop during the punching operation. To this end the frame I has reciprocably mounted in the cylindrical opening I9 t e plunger 29. The outer end 2| of the plunger is in the form of a semicylinder, the upper flat face 22 of which serves as a seat for the punch I5 during the punching operation. 'The reciprocation of the plunger 29 is controlled by the trigger 23 which is connected to the plunger by the Bowden control, such as slidably mounted within the tubular casing 25.- The trigger 23 is held in-the normal retracted position, shown by the full linesin Fig. l by the tension spring 29, one end of which is secured to the trigger and the other end to the frame I.

Since the punch I5 during riveting operation acts as a portion of the anvil, therefore the upper end of the punch must be flush with the face 28 of the anvil. To insure this flush relation beface of the anvil both at initial installation and subsequently when the punch is ground to size after being worn down by use, an adjustable stop 21 is threaded into the frame I beneath and in alignment with the punch I5. By screwing the adjustable stop 21 inwardly or outwardly the same can be adjusted so that when the punch I5 is in fully depressed position, as shown in Fig. 6, for instance, the lower end 28 of the punch I5 will be seated upon the stop 21 and the upper end of the punch |5 will be flush with the upper face 26 of the anvil.

The head 4 is provided with a pair of cylinders 39 (Fig. 2) and 3| (Fig. 5) in which are rotatably and reciprocably mounted the plungers 32 and 33 respectively. Since the plungers 32 and 33 are the same a description of one will serve as a description of the other. The plunger 32 is hollow and has mounted therein the tension coil spring 34, one end of which is secured to the plunger 32 as at 35 and the other end of which is secured in the cap 36 which is threaded in or otherwise fixed to the upper end of the cylinder 39 for closing the same. The spring 34 is a tension spring and normally holds the plunger 32 in raised or retracted position. The plunger 32 has splined thereon the bell crank 31 provided with a spline 38 which slidably engages the longitudinal spllneway 39 in the plunger 32. The bell crank 31 is rotatably supported in the slot 49 in the wall of the cylinder 39. Hence, the plunger 32 is free to move upwardly and downwardly relative to the bell crank 31 but owing to the spline 38 and splineway 39 must rotate with the bell crank 31.

The plunger 33 has splined thereon the crank 4| in the same fashion as the bell crank 31 is splined on to the plunger 32. The crank 4| is also rotatably mounted in a slot in the wall of the cylinder 3| the same as the slot 4| in the wall of the cylinder 39 so that the plunger 33 has to rotate with the crank 4| but can slide upwardly and downwardly relative thereto. The

cranks 4| and 31 are connected by the link 42 as at 43 and 44 respectively.- The bell crank 31 is connected to the trigger 23 by the Bowden control 45.

The plunger 32 supports and preferably has formed integrally therewith, the die carrier 48 which carries the die 41. The die 41 is provided with the opening 48 for ejecting the slugs of metal during the punching operation and is provided with an opening 49 for receiving the end of the driving pin 8. When the trigger 23 is in released position the die 41 is positioned beneath the tool 6 as shown in Figs. 1 and 3. If the'trigger 23 is now pulled upwardly or .to the position shown in the dotted lines in Fig. l, the Bowden wire 45 moves to the left causing the bell crank 31 'to move clockwise as viewed in Fig. 3, thus causing the plunger 32 to rotate clockwise, swinging the die 41 from beneath the set 8. The rotation of the bell crank is transmitted through link 42 to crank 4| thus causing plunger 33 to rotate clockwise and in turn swing the rivet shoe 59 beneath the set 8.

The rivet shoe 59 is shown in detail in Figs. 5, 9 and 10. The lower end of the plunger 33 carries the pin 5| upon which is rotatably mounted the two similar halves 52 and 53 which form the rivet shoe 59. The parts 52 and 53 of the rivet shoe are held together bythe spring 54, one end of which is secured to the part 53 at 55 and the other end of which is secured to the part 52 as at 55. The shoe 58 is held on the pin by the arm 51 which is mounted in fixed relation on the pin 5|. Since the shoe 58 is formed of the two parts 52 and 53 which are yieldably held together by the spring 54 and which are rotatably mounted upon the pin 5| the shoe 55 is free to float about the pin 5|. It is essential that the shoe rotate with the plunger 33.

Therefore, the arm 51 carries the pin 58 which fits between the parts 52 and 53 and thus causes the shoe 5|] to rotate with the shaft 33. The parts 52 and 53 have the semi-cylindrical recesses 80 and 8| respectively in their abutting faces which when in opposed matched relation cooperate to form the cylindrical opening 55 which receives the stem of the rivet. The parts 52 and 53 likewise have semi-conical recesses which cooperate to form the conical mouth 53 this example, cylindrical) for opening 55 so that the rivet upon being. fed to the shoe will with certainty be .received in the rivet opening 55.

Since the rivets are to be pneumatically or otherwise forcibly fed into the rivet shoe, to this end the head has secured thereon the rivet magazine 5| provided with a removable cap 52. The magazine 5| is in the form of a tube. the lower end of which is open and preferably approximately the same diameter as that of the rivet head. The lower end or mouth of the rivet magazine 5| is surrounded by a plurality of spring fingers 53 which depend from the end of the magazine and then turn somewhat .inwardly as at 54. These spring fingers serve to yieldably hold the lowermost rivet by the head.

The rivets are arranged to be fed into the magazine 5| stem first, as shown, and the cap 62 fastened in place. Although the rivets are arranged to be pneumatically fed to the rivet shoe 50 preferably the compressed air produced on the return stroke of the piston may be utilized to pufif or pneumatically force the rivet fromthe grip of the spring fingers 53 into the shoe 58. To this end the magazine 5| is connected with the inside of the cylinder by means of the tube 55. The tube 55 communicates with the opening 55 which in turn communicates with the exhaust port 61 in the cylinder head. The communication between the openings 55 and 51 is controlled by the ball .valve 58 which is yieldably held against the valve seat by the coil spring 59. The ball valve 58 may be thrown to open position by the plunger 15 when it is moved to the left by the trigger 9, as shown at Fig. 1.

Since a gush of air passes through the megazine 5| upon each return stroke of the plunger 5 and the rivets act in the nature of a piston, it is necessary to prevent the rivets from being released by the spring finger 53 when the rivet shoe 55 is not beneath the magazine. To this end a rivet stop inthe form of a platform 1| is mounted on the ends ofthe spring fingers 12 mounted on opposite sides of the magazine as at 13 and 14.

In case the riveting machine is to be used upside down a suitable :oil spring 95 may be inserted in the rivet magazine 5| to yieldably back up the rivets in the magazine. If desired, the coil spring 95 may be used to eject the rivets from the magazine instead of pneumatically ejecting them by the exhaust. In such case the coil spring will be of suflicient strength to eject the rivet from the spring fingers 54 into the rivet shoe when the rivet stop 1| is removed.

Since it has been found expedient in some cases to use a lighter blow for riveting than for punching,-it is proposed to decrease the intensity of the riveting blows by throttling the exhaust. To this end the exhaust valve I2 (Fig. 2) has slidably mounted thereon the sleeve I40 which is arranged to partially close the exhaust port MI. The sleeve I40 is provided with an arm I42 which has adjustably connected thereto the rod I53 which is pivotally connected to the bell crank arm 31 as at I. The rod I43 is adjustably connected to the arm I42 so that the amount the sleeve I45 throttles the exhaust port I4! can be varied. The adjustable connection between the arm I42 and the rod I43 can be effected in any suitable way such as by threading the end of the rod I43 on each side of the arm I42 and providing the threaded end of the rod with a nut, one on each side of the arm I42, the one nut serving as a locking nut for the other when the arm is adjusted to the position desired. Inasmuch as the rod 143 is connected to the bell crank 31 the throttling of the exhaust port I4| will be effected by operation of the trigger 23 which, through the Bowden control 45 controls the crank lever 31. It is, of course, understood that this means of controlling the throttling of the exhaust port is shown by way of example only.

The operation of the device is as follows: The operator releases triggers 9 and 23, at this time the plunger 10 is thrown to the left, as shown in Fig. 1, thus opening the ball valve 58 to permit the exhaust of the return stroke of the piston to pass through the rivet magazine. At this time likewise the die 41 is positioned beneath the set 5 and the punch seat 20 is in the projected position shown in Fig. 2, with the face 22 in position to receive the lower end 28 of the punch I5. At this time the operator places the work or metal sheets which are to be riveted upon the punch I5 in the proper position. The operator then pulls the trigger 3 to the middle position, shown in the dotted lines in Fig. 1. This causes the arm I3 of the bell crank trigger 3 to depress the plunger I3I of the intake valve 8 to open the same but does not affect the exhaust valve plunger I23. This opens the air line 1 so that the compressed air is fed to the pneumatic motor whereupon the plunger 5 and set 5 move downwardly on the power stroke, the set 5 first seating itself in the seat 45 of the die 41 and then forcing the die downwardly till it engages the metal sheets which are to be riveted together. If the initial power stroke is strong enough. i. e., exerts a stress beyond the yield point of the metal being punched, the punch I5 will pierce the metal sheets 15 and the slug will be ejected through the opening 48. This will often occur if the metal stock is of thin enough gauge. If the initial punch is not strong enough to do this. the operator then pulls the trigger to the full open position shown in Fig. 2 thus causing the arm I22 to depress the plunger I23 and open exhaust valve I2 which causes piston I24 to vibrate or reciprocate and in turn the set 5 and die 41 to vibrate or reciprocate. These intermittent exhaust port I.

to pierce the metal sheets 15 to form the hole for the rivet. Each of these successive blows is light enough to be within the yield point 01' the particular metal being punched.

After the hole is vibrated through the metal sheets 15, trigger 3 is released thus causing the plunger'lfl toopen the ball valve 68 and permitting the return stroke of the plunger 5. As the plunger moves upwardly the exhaust passes through the opening 31, past the ball valve, through the conduit 66 and tube 65 into the magazine 5!. This exhaust of air through the magazine 5| puil's" or pneumatically forces the lowermost rivet from the grip of the curved finger ends 84 into the rivet shoe 50, as shown in Figs. 4 and 5. (At this time rivet shoe 53 is in the position shown in Figs. 3 and 4, that is, directly beneath the magazinetl with the rivet stop H pushed to. one side.) The trigger 9 being released the operator now pulls upwardly on the trigger 23 to move the same to the dotted line position shown in Fig. 1. The punch i5 is still yieldably held in raised position by the coil spring l6 and remains in the hole through the metal sheets 15 and thus keeps them properly positioned. As the trigger 23 is pulled to the dotted line position, this retracts the plunger 20 from beneath the lower end 23 of the punch l5 to the position shown in Fig. 6, and at 45 swings the.

the same time the Bowden wire bell crank 37 clockwise which rotates the shaft 32 and through the link 42 rotates the shaft 33 thus causing the die to be swung from beneath the set 6 and the loaded rivet shoe 50 beneath the 35 set 6. The removal of the rivet shoe 50 from beneath the magazine 6| permits the step ii to spring back into the position shown in Fig. 12 directly beneath the spring finger 53. At this time the operator again pulls the trigger 9 which l0 causes the plunger 5 and set 5 to descend carryin with it the loaded rivet shoe 55 to the position shown in Fig. 5. The rivet is then upset by the initial power stroke of the set 6 or by subsequent vibration or reciprocation of the set.

l5 As the trigger 23 is pulled to the dotted line position, it acts through the Bowden wire 45 to swing the bell crank lever 31 clockwise which draws rod I43 to the left. This in turn causes the throttling sleeve I40 to partially close the Inasmuch as the exhaust port |4l is partially throttled, a certain amount of air is'entrapped within the cylinder and this cushions the power stroke of the reciprocating piston I24 within the plunger 5. This cushioning action,

' due to the throttling of the exhaust. in turn weakens or decreases the energy content of each of the successive blows given the rivet by the reciprocating piston I24 acting through set 5. The weakening of theenergy content of the blow 0 given by the reciprocating piston is proportionate to the throttling of the exhaust port I, that is,

the more the exhaust port is throttled or closed by the throttling sleeve the weaker the blow.

As the set 6 descends it engages the sides of 5 the conical opening 59 of the work shoe forcing the parts 52 and 53 apart, shown in Figs. 7 and 8, thus releasing the rivet from the work shoe. As the rivet is forced downwardly by the pin 6 it engages the upper end of the punch l5, de-- presses the same and follows the same through the hole which has been previously punched in the metal sheets 15. The punch l5 can retreat because the plunger 20 is in the position shown in Fig. 6. The punch I5 retreats until the lower end 28 engages the adjustable stop 2'! which 2,056,559 vibratory blows will in turn force the punchlicates the upper end of the punch l5 flush with the face 25 of the anvil l4. Thus the punch cooperates with the anvil M to form an anvil for riveting over the stem of the rivet.

The operator now releases the trigger 3 which moves to the left or full line position as shown in Fig. 1. The plunger 5, inasmuch as the air line I is now cut oil", now makes its return stroke exhausting the air as above described through the magazine BI and permits the coil spring 34 to raise the plunger 33 and the rivet shoe. At this time the rivet shoe is not beneath the rivet magazine but the lower rivet will not be pufled or pneumatically ejected from the spring fingers 63 because stop II is now beneath the spring fingers. As soon as the trigger 23 is released, the spring 23 will return it to its original full line position thus causing the Bowden wire 45 to move to the right as viewed in Fig. 3. This movement of the Bowden wire 45 acting through the oi ank 31, link 42 and crank 4| again moves the die 41 directly beneath the set 6 as shown in Fig. "l and the rivet shoe beneath the magazine 6| #s shown in Figs. 3 and 4. As the rivet shoe 50 "moves beneath the spring fingers 63, it swings the stop H to one side and thus is in position to again receive the lowermost rivet upon the return stroke of the piston when the punching is completed if the rivets are fed to the shoe pneumatically, but receives the lowermost rivet as soon as the stop H is removed if the rivets are fed by spring 30.

I claim:

1. In a machine of the type described, a work performing tool, a pneumatic motor ofthe reciprocable type for actuating said work performing tool to effect a blow of a given energy content, the said pneumatic motor having an exhaust port, and means for throttling said exhaust port to vary the energy content of the blow effected by said tool.

2. In a machine of the type described, a work performing tool, a pneumatic motor of the reciprocable type for actuating said work performing tool to effect a blow of a given energy content, the said pneumatic motor having an exhaust port, and an adjustable closure for partially closing thesaid exhaust port to vary the energy content of the blow.

3. In a riveting machine having an anvil for receiving the work and a pneumatic motor having a cylinder and. a reciprocable plunger for cooperating with the said anvil to upset the rivet, a rivet magazine adapted to receive a plurality of rivets and having an outlet, a rivet shoe receiving the rivets from said outlet for positioning them to befed to the work and upset by said plunger, an exhaust outlet in said cylinder communicating with the said magazine whereby the exhaust created by the return stroke of the plunger pneumatically ejects the rivets from the said rivet magazine into the said rivet shoe.

4. In a riveting machine having an anvil for I receiving the work and a pneumatic motor having a cylinder and a reciprocable plunger for exhaust created by the return stroke of the plunger pneumatically, ejects the rivets from the said rivet magazine into said rivet shoe.

5. In a riveting machine of the type having an anvil for receiving the work, and a pneumatic motor of the type having a cylinder and a reciprocable plunger tor cooperating with the said anvil to upset the rivet, a rivet magazine adapted to receive a plurality of rivets and having an outlet, 9. rivet shoe receiving the rivets from said outlet for positioning them to be fed to the work and upset by said plunger, a plurality of spring fingers adjacent the outlet of the said rivet magazine for yieldably holding the rivets therein, an exhaust outlet in said cylinder communicating with the said magazine whereby the exhaust created by the return stroke of the V plunger pneumatically ejects the rivets from the said rivet magazine into said rivet shoe.

6. In a combined punching and riveting machine comprising an anvil for receiving the work, a pair of cylinders, each of said cylinders having a plunger rotatably and slidably mounted therein, a die mounted on one of said plungers, a rivet shoe mounted on the other of said plungers, an operative connection between the said plungerswhereby the plungers rotate simultaneously, a punch reciprocably mounted within the said anvil, power means including a driving pin alternately cooperating with said die and punch for punching the work and with the rivet shoe and anvil for upsetting the rivet, a retractable-punch. seat positioned beneath the inner end of 'the said punch whereby the outer end of the punch projects beyond the work face of the anvil during the punching operation, and means operatively connected to the said plungers and to the retractable punch seat for alternately positioning the die and shoe between the anvil and the driving pin and for retracting the punch seat from the inner end of the punch when the rivet shoe is between the anvil and the driving pin whereby the outer end of the punch retreats to a position flush with the work face of the anvil to serve as a part of the anvil to upset the rivet.

7. In a machine of the type described, an anvil, a punch retractably mounted within the anvil, resilient means operatively connected to said punch for projecting the punch beyond the work face of the anvil, a retractable seat for the said punch for holding the same in proiected position during the punching operation, and an adjustable stop for the said punch for aligning the outer end of the punch flush with the work face of the anvil during the riveting operation whereby the punch serves as a part of the anvil during the riveting operation.

8. In a riveting machine of the type having an anvil for receiving the work, a rivet magazine having an outlet at one end adapted to receive a plurality of rivets in the form of a stack, a shiitably mounted shoe positioned beneath the outlet end of the magazine for transferring the rivets from the magazine to the work upon the anvil and for supporting the stack of rivets when positioned beneath the outlet end of the magazine, a retractable stop positioned beneath the outlet end of the said magazine in the path of movement of the said shiftable shoe for supporting the stack of rivets within the magazine whereby the stop is engaged and retracted from the outlet end of the magazine by the rivet shoe when the shoe is shifted beneath the outlet end of the magazine for receiving a rivet and the rivet stack is alternately supported by the shoe and the retractable stop, and resilient means for effecting a thrust upon the said rivet stack to eject one of the rivets from the magazine into the said rivet shoe when the rivet stop is retracted from the outlet of the magazine.

HENRY A. BERLINER. 

